The basic principles of electrostatographic printing with dry marking material (hereinafter generally referred to as “xerography,” “xerographic printing,” and/or the like) are well known: an electrostatic latent image is created on a charge-retentive surface, such as a photoreceptor or other charge receptor, and the latent image is developed by exposing it to a supply of toner particles, which are attracted as needed to appropriately-charged areas of the latent image. The toner particles are then transferred in image-wise fashion from the charge receptor to a print sheet, and the print sheet is subsequently heated to permanently fuse the toner particles thereto and form a durable image. Following the transfer of the image from the charge receptor to the print sheet, residual toner particles and/or other debris left on the charge receptor are typically removed by a blade, a brush, a mesh/web, a vacuum, and/or one or more other suitable “cleaning” or “spot removal” devices. The removed debris is typically accumulated in a hopper and then directed, typically by an auger, into a waste container.
Systems that have employed one or more cleaning blades to separate the debris from their charge receptors have included solenoid driven mechanisms for engaging and disengaging the cleaning blades with the charge receptors. Solenoid drives have generally facilitated simple, low cost, and reliable cleaning blade actuation.
However, an under-damped solenoid drive can cause a cleaning blade to impact or strike the charge receptor at an undesirably high speed on engagement. The resulting abrupt change in frictional drag on the charge receptor can cause motion quality errors and associated image defects for a belt type or a drum type photoreceptor and, additionally, it can cause transverse waves and associated undesirable variations in development for a non-contacting belt type photoreceptor.
Meanwhile, an over-damped solenoid drive can prevent a cleaning blade from cycling (i.e., engaging, disengaging, and then re-engaging a charge receptor) fast enough to meet increasingly high imaging speed demands and/or from moving abruptly enough to facilitate swiping and/or throwing of residual toner from the cleaning blade.
Thus, there is a need for a solenoid driven cleaning blade control apparatus and method that can prevent the cleaning blade from impacting a charge receptor at an undesirably high speed and yet can also still cycle the cleaning blade at high speeds and/or move the cleaning blade abruptly enough to facilitate swiping and/or throwing of residual toner therefrom.